A feature of socket wrenches which makes them very easy to use is the one-way ratchet connection between the wrench handle and the socket receiving stub, so that once a wrench socket is engaged with a bolt head the handle can be turned clockwise to tighten the bolt and turned counterclockwise to start a new stroke without having to disconnect the socket from the bolt head. Socket wrenches, however, have the disadvantage that a different socket is required for each size bolt head.
There are several varieties of adjustable wrenches, but to the best of applicant's knowledge all adjustable wrenches must be disengaged from a bolt head and re-engaged on each stroke. This is particularly time-consuming where the location of the bolt to be tightened is such that nearby obstructions limit the length of the wrench stroke and thus necessitate frequent disconnection and reconnection of the wrench with the bolt head. In this respect adjustable wrenches are similar to spanners, hex wrenches and box wrenches.